Flotation-separation of nickel from aqueous media using some hydrazone derivatives as organic collectors and oleic acid as surfactant

Abstract

A simple and rapid procedure was developed for the quantitative flotation of nickel(II) from aqueous solutions. Hydrazone derivatives such as: 4-acetylpyridine-[N-(3-hydroxy-2-naphthoyl)]hydrazone (H₂APHNH), thiophene-2-carbox- aldehyde-[N-(3-hydroxy-2-naphthoyl)]hydrazone (H₂THNH), salicylaldehyde-[N-(3-hydroxy-2-naphthoyl)]-hydrazone (H₂SHNH), <i style="">p</i>-anisaldehyde-[N-(3-hydroxy-2-naphthoyl)]hydrazone (H₂-<i style="">p</i>-AHNH) and ethylacetoacetate-[N-(3-hydroxy-2-naphthoyl)]hydrazone (H₂EHNH) have been used as organic collectors and oleic acid as surfactant. The different parameters, affecting the flotation process, namely, ligand and surfactant concentrations, foreign ions (which are normally present in fresh and saline waters), pH and temperature are examined. Nearly 100% of nickel ions are floated at a metal:ligand ratio of 1:2, pH ~ 7 and at a temperature ~ 25ºC. The procedure is successfully applied to recover Ni(II) from some water samples. The flotation mechanism is suggested.